1. Field of the Invention
This invention relates to a method for subcutaneously electrically stimulating peripheral nerves and in a particular embodiment relates to a method for subcutaneously electrically stimulating one or more occipital peripheral nerve to treat occipital neuralgia.
2. Description of Related Art
Peripheral nerves are nerves in the body other than the nerves of the brain or spinal cord. Peripheral nerve injury may result in the development of chronic intractable pain. Some patients prove unresponsive to conservative pain management techniques. Peripheral Nerve Stimulation (PNS) has developed as a successful therapy for pain management when the pain is known to result from a specific nerve. PNS is based in part on the Melzack-Wall gate control theory of pain. Sweet and Wespic first used electrical stimulation of peripheral nerves in the 1960s to mask the sensation of pain with a tingling sensation (paresthesia) caused by the electrical stimulation. Subsequent refinements in the technology, surgical technique and patient selection have led to improved long term results.
PNS is an accepted alternative for those patients who have failed more conservative pain management therapies. Clinical experience has shown that when applied to appropriate patients by trained practitioners, PNS can reduce pain, reduce narcotic intake to manage pain and improve the patient""s activity levels and their quality of life. PNS has been recognized to have the following desirable characteristics:
The surgical procedure is relatively simple.
PNS is nondestructive. No known permanent surgical or chemical interruption of nerve pathways occurs.
PNS is reversible. If the patient does not benefit, the device can be turned off or removed. There are no known long-lasting medical or surgical side effects.
Patients can be tested for response prior to implant of the complete system.
Occipital nerves 2, 4 and 6 (FIG. 1) are peripheral nerves that exit the spinal cord at the C2 level of the cervical vertebrae and extend upward generally along the back and back-sides of the head. The lesser occipital nerve 2 extends upward and toward the sides of the head. The greater occipital nerve 4 extends upward toward the top of the head. The third occipital nerve 6 extends from near the neck around the back of the head toward the ear. Because of the location where the occipital nerves leave the spinal cord, the occipital nerves pass from the spinal column through muscle and fascia to the scalp.
Occipital neuralgia is a condition characterized by paroxysms of pain occurring within the distribution of the greater and/or lesser occipital nerves. Occipital neuralgia has been described as a xe2x80x9cjabbingxe2x80x9d pain in the area of the greater or lesser occipital nerve. The pain may radiate from the back or sides of the head toward the top or front of the head. Patients will vary in their reporting of this pain. It has been characterized in the medical literature as a unilateral or bilateral throbbing pain that frequently radiates to the forehead and to the frontal region (Stechison and Mullin, 1992) or as a lancinating pain extending from the suboccipital region up to the top of the head. The pain is less often described as including or consisting of a dull achingxe2x80x9d (Sulfaro and Gobetti, 1995). Occipital neuralgia is often accompanied by diminished sensation and sometimes extreme localized tenderness over the applicable nerve.
Though known causes of occipital neuralgia include closed head injury, direct occipital nerve trauma, neuroma formation or upper cervical root compression (spondylosis or ligamentous hypertrophy), most patients have no demonstrable lesion. An anesthetic block of the greater occipital nerve can be used to confirm the diagnosis of occipital neuralgia (Khun, et al., 1997).
Traditional treatment options for intractable occipital nerve pain that has proven to be resistant to medications usually involve chemical, thermal or surgical ablation procedures following diagnostic local anesthetic blockade. Surgical approaches include neurolysis or nerve sectioning of either the occipital nerve in the occipital scalp or at the upper cervical dorsal root exit zone (extradural). Forammal decompression of C2 roots as well as C2 ganglionectomy have also been effective in reported cases.
Many patients with occipital neuralgia do not favorably respond to these medical treatments. Therefore, there is a need for an additional effective treatment of occipital neuralgia.
A method for treating pain by subcutaneous electrical stimulation is disclosed. A lead is placed subcutaneously over (superior to) a peripheral nerve that is causing pain The nerve is electrically stimulated to cause paresthesia. As a result, the pain is masked. The method of the invention encompasses subcutaneous placement of an electrical lead near any peripheral nerve causing pain and subsequent electrical stimulation of the nerve to cause paresthesia.
In particular, a method for treating intractable occipital neuralgia using percutaneous peripheral nerve electrostimulation techniques is disclosed. The method involves a subcutaneous electrode placement at the level of C1 transversely across the base of the occipital nerve trunk and subsequent electrical stimulation of the occipital nerve trunk. This stimulation produces paresthesia and pain relief covering the regions of occipital nerve pain
It is therefore an object of the invention to provide a method for subcutaneously electrically stimulating nerves causing pain to create paresthesia.
It is another object of the invention to provide a method for percutaneously placing leads subcutaneously to create paresthesia.
These and other object of the invention will be clear from the following detailed description of the invention.